Self-aligning apparatus for idler roll assembly

ABSTRACT

An actuating roll is carried by and mounted for rotation adjacent an end of a swivel mounted idler roll assembly with the upper surface thereof extending outwardly and upwardly to engage and support the adjacent edge of a belt upon lateral off center movement of the belt toward the roll. A brake subjacent the roll engages the under surface of the roll upon downward movement of the roll. The actuating roll is retained out of engagement with the brake until a predetermined force is exerted thereon by the belt.

United States Patentv 11 1 Morrison Dec. 11, 1973 SELF-ALIGNING APPARATUS FOR IDLER ROLL ASSEMBLY Primary Examiner-Even C. Blunk [75] Inventor: Thomas E. Morrison, Guin, Ala. jifgifgf ffigfi gzigfzfg z [73] Assignee: Continental Conveyor and Equipment Company 57] ABSTRACT [22] Filed: 1972 A11 actuating roll is carried by and mounted for rota- [21] Appl. No.: 313,841 tion adjacent an end of a swivel mounted idler roll assembly with the upper surface thereof extending outwardly and upwardly to engage and support the adjacent edge of a be upon lateral off center movement [58] d Egg/202 of the belt toward the roll. A brake subjacent the roll 1e 0 earc engages the under Surface of the roll upon downward [56] R f C d movement of the roll. The actuating roll is retained e erences out of engagement with the brake until a predeter- UNITED STATES PATENTS mined force is exerted thereon by the belt.

1,963,099 6/1934 Robins 198/202 3,603,451 9/1911 Promin et al. 198/202 7 Claims, 6 Drawmg Flgum F 3 1 E 32 I? a I6 32 2? 22\ I3 I 1 r 3 f 15 m i f I6 I lfi IE [5 /6 4 +5 .1242) 1.1 Lil 1 1'f5: ;L::J 1-- ;l g i 47 4 I F /5 47' LL-JI 3 l0 SELF-ALIGNING APPARATUS FOR IDLER ROLL ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to apparatus for self aligning a swivel mounted idler roll assembly extending transversely of and supporting a conveyor belt about a point on the conveyor center line and more particularly to self aligning means which prevents the conveyor belt from shifting off center, thus eliminating belt damage and material spillage.

As is well known in the art to which my invention relates, many self aligning idler roll assemblies have been proposed. Such assemblies are alike in that a top half of the roll supporting the belt swivels about a point on the conveyor center line so that roller rotation exerts a sidewise force on the belt to force the belt back toward normal center path. That is, the end of the roller on the side toward which the belt has shifted is moved forward in the direction of belt travel. The self aligning idlers may be either troughing for supporting the material conveying portion of the belt or may be flat for the return portion of the belt.

BRIEF SUMMARY OF THE INVENTION My improved apparatus relates to. the actuating means employed to bring about automatic swiveling of the idler roll assembly to train the belt. An actuating roll is carried by and mounted for rotation adjacent each end of a swivel mounted idler roll assembly with the upper surface of each actuating roll extending outwardly and upwardly in position to engage and support the adjacent edge of the conveyor belt upon lateral movement thereof toward the actuating roll. The force required to accelerate and overcome the friction of the actuating roll acts to swivel the idler assembly and thus train the belt. A stationary braking surface is provided subjacent the actuating roll in position to engage the under surface of the actuating roll upon downward movement of the roll a predetermined distance. The actuating roll is retained out of engagement with the braking surface until a predetermined force is exerted on the roll by the belt in response to lateral off center 'movement of the belt into engagement with the roll to move the actuating roll into engagement with the braking surface. Accordingly, should the belt continue to move off center after engaging the actuating roll it will climb further up on the actuating roll to overcome the force exerted by the supporting or retaining means for the actuating roll. This braking of the actuating roll results in a dragging action between the belt and the top of the actuating roll to thus swivel the idler roll assembly and train the conveyor belt. At the same time, the brake against the bottom of the actuating roll produces an equal force in the same belt travel direction as the actuating roll tries to roll along the braking surface. Continued off center movement of the conveyor belt increases the braking and dragging forces in proportion to the actual belt weight placed on the actuating roll.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a swivel mounted idler roll assembly having my improved self aligning apparatus associated therewith;

FIG. 2 is a top plan view of the apparatus shown in FIG. 1, parts being broken away for the sake of clarity;

FIG. 3 is an end elevational view, partly broken away, taken generally along the line 33 of FIG. I and drawn to a smaller scale;

FIG. 4 is an enlarged, fragmental view taken generally along the line 4-4 of FlG. 2;

FIG. 5 is a view taken generally along the line 5-5 of FIG. 4, parts being broken away; and,

FIG. 6 is a view taken generally along the line 6-6 of FIG. 4.

Referring now to the drawings for a better understanding of my imnvention, I show a self-aligning idler swivel assembly 10 which is pivotally connected by a pivot pin 11 to a suitable supporting structure 12. The idler swivel assembly 10 comprises idler rolls 13 which are mounted for rotation on stationary shafts 14 having suitable grease fittings 16, as shown. The ends of the shafts 14 are supported by suitable transverse support members 17 whereby the rolls 13 are adapted for rotation on the shafts 14 in the usual manner. The rolls 13 are shown as comprising a plurality of spaced, rubber disc belt supporting roll elements 18 which are adapted to flex to shake off material build up on the conveyor belt indicated at 19. In view of the fact that the idler swivel assembly 10 and the supporting frame 12 are of a conventional type, no further description thereof is deemed necessary.

Mounted adjacent each end of the idler swivel assembly 10 by suitable retaining bolts 21 is an upstanding support bracket 22 which extends generally parallel to the rolls 13, as shown in FIG. 2. Secured to and projecting laterally from each support bracket 22 are a pair of lateral support arms 23 and 24. As shown in FIG. 5 the support arms 23 and 24 are provided with upwardly opening recesses 26 and 27, respectively for receiving retaining nut assemblies 28 and 29, respectively, provided at opposite ends of a shaft 31. Mounted for rotation on the shaft 31 is an actuating roll 32 which is mounted in position for the upper surface thereof to extend outwardly and upwardly, as shown in FIG. 1. As shown in FIGS. 4 and 5, the retaining nut assembly 28 is held against rotation relative to the lateral support bracket 23 by a retaining cap screw 33 which passes freely through an opening 33a provided in a projection 33b on the nut assembly 28 whereby the nut assembly 28 is adapted for pivotal movement relative to the bracket 23. The assembly 29 is adapted for free vertical movement in the upwardly opening recess 27. The outer end of the shaft 31 for the actuating roll 32 is secured to an elongated spring member 34 by an inverted U-shaped member 36. As shown in FIG. 5, the elongated spring member 34 is generally L-shaped, as viewed in plan. The end of the elongated spring 34 opposite the end connected to shaft 31 is secured to the support bracket 22 by a retainer bolt 37 having a nut 38. A suitable washer 39 engages the outer surface of the elongated spring 34, as shown, to firmly anchor the spring 34 to the support bracket 22. The free end of the elongated spring 34 extends beneath a spring stop 41 having an under surface 42 in position to engage the free end of the spring 34 and thus limit upward movement thereof.

Mounted on the support bracket 22 intermediate the ends of the elongated spring member 34 is a sleeve-like member 43 which carries a spring adjusting screw 44. The upper end of the adjusting screw 44 is adapted to engage the under surface of the spring 34 and thus hold the spring and the shaft 31 secured thereto at selected vertical positions. The adjusting screw 44 is secured in selected positions by a lock nut 46. Mounted on the stationary supporting frame 12 adjacent each end of the idler swivel assembly is an inwardly extending support bracket 47 which carries a brake member 48. Each brake member 48 is provided with an upper surface 49 which extends parallel to the adjacent outer surface of the actuating roll 32. Accordingly, upon downward movement of the actuating roll 32, the outer surface of the actuating roll engages the braking surface 49.

From the foregoing description, the operation of my improved apparatus for self aligning the swivel mounted idler assembly 10 will be readily understood. As the belt 19 moves off center its straying edge contacts the upwardly and outwardly sloping surface of the actuating roll 32. That is, the upper surface of the actuating roll 32 extends upwardly and outwardly from the end of the idler roll 13, as shown in FIG. 1. The force required to accelerate and overcome the friction of the actuating roll 32 acts to swivel the idler assembly 10 and thus train the belt 19. In the event the belt 19 continues to move off center, it will climb further up on the actuating roll 32, thereby overcoming the preloaded spring 34 which supports the outer end of the actuating roll 32 whereby the actuating roll 32 is moved downwardly into contact with the braking surface 49. Since the brake member 48 is carried by a stationary supporting surface, the braking action of the actuating roll 32 results in a dragging action between the belt 19 and the top of the actuating roll 32 thus tending to swivel the idler assembly 10 and train the belt 19. At the same time the braking surface 49 engages the under surface of the rotating actuating roll 32 to thus produce an equal force in the same belt travel direction as the actuating roll tries to roll along the braking surface 49. If the brake still continues to move off center, braking and dragging forces for swiveling continue to increase as more belt weight is placed on the actuating roll. Accordingly, the braking action and dragging force is proportional to the weight of the belt 19 which actually moves onto the actuating roll 32.

From the foregoing, it will be seen that l have devised an improved self aligning unit for a swivel mounted idler roll assembly. By providing an actuating roll 32 anchored to the swivel mounted self aligning idler assembly 10 which is braked by the braking surface 49 carried by the fixed frame 12, I increase the actuating force imparted to bring the belt back to its proper position on the idler rolls. Also, the addition of the resilient spring 34 which regulates the braking force on the bottom of the actuating roll 32, the actuating roll 32 can be caused to slip on the braking surface 49 instead of the belt, thus providing long trouble free operation of my improved apparatus. It will thus be seen that my improved apparatus is adapted for use on reversible belts and is particularly adapted for use on dirty, return belts and rubber. disc rolls. In actual practice, I have found that by gradually increasing the swiveling force, better performance is obtained than with counterweighted disc-type self aligning units. With my improved apparatus no scuffing of the belt occurs against stationary surfaces and at the same time I double the swiveling force by pairing the belt drag on the upper surface of the actuating roll with the braking action force on the under surface of the actuating roll.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What I claim is:

1. In apparatus for self aligning a swivel mounted idler roll assembly extending transversely of and supporting a conveyor belt about a point on the conveyor centerline:

a. an actuating roll carried by and mounted for rotation adjacent an end of said idler roll assembly with the upper surface of said actuating roll extending outwardly and upwardly in position to engage and support the adjacent edge of said belt upon lateral off center movement of said belt toward said actuating roll,

b. a brake member having a braking surface subjacent said actuating roll in position to engage the under surface of said actuating roll upon downward movement of said actuating roll a predetermined distance, and

c. means retaining said actuating roll out of engagement with said braking surface until a predetermined force is exerted on said actuating roll by said belt in response to said lateral off center movement of said belt into engagement with said actuating roll to move said actuating roll into engagement with said braking surface.

2. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 1 in which said brake member is carried by a stationary support adjacent the end of said idler roll assembly which carries said actuating roll.

3. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 1 in which an actuating roll is mounted adjacent each end of said idler roll assembly with abrake member subjacent each actuating roll.

4. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 1 in which said means retaining said actuating roll out of engagement with said braking surface comprises resilient means urging said actuating roll away from the subjacent braking member.

5. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 4 in which said resilient means comprises a spring member supporting the outer end of said actuating roll.

6. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 5 in which said spring member is an elongated spring anchored at one end to said idler roll assembly with the other end thereof connected to the outer end of said actuating roll.

7. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 6 in which an adjustable support member engages and supports said spring member intermediate the ends thereof to retain said actuating roll at selected elevations. 

1. In apparatus for self aligning a swivel mounted idler roll assembly extending transversely of and supporting a conveyor belt about a point on the conveyor centerline: a. an actuating roll carried by and mounted for rotation adjacent an end of said idler roll assembly with the upper surface of said actuating roll extending outwardly and upwardly in position to engage and support the adjacent edge of said belt upon lateral off center movement of said belt toward said actuating roll, b. a brake member having a braking surface subjacent said actuating roll in Position to engage the under surface of said actuating roll upon downward movement of said actuating roll a predetermined distance, and c. means retaining said actuating roll out of engagement with said braking surface until a predetermined force is exerted on said actuating roll by said belt in response to said lateral off center movement of said belt into engagement with said actuating roll to move said actuating roll into engagement with said braking surface.
 2. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 1 in which said brake member is carried by a stationary support adjacent the end of said idler roll assembly which carries said actuating roll.
 3. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 1 in which an actuating roll is mounted adjacent each end of said idler roll assembly with a brake member subjacent each actuating roll.
 4. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 1 in which said means retaining said actuating roll out of engagement with said braking surface comprises resilient means urging said actuating roll away from the subjacent braking member.
 5. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 4 in which said resilient means comprises a spring member supporting the outer end of said actuating roll.
 6. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 5 in which said spring member is an elongated spring anchored at one end to said idler roll assembly with the other end thereof connected to the outer end of said actuating roll.
 7. Apparatus for self aligning a swivel mounted idler roll assembly as defined in claim 6 in which an adjustable support member engages and supports said spring member intermediate the ends thereof to retain said actuating roll at selected elevations. 